Method of manufacturing light-emitting display device and light-emitting display device manufactured using the method

ABSTRACT

A method of manufacturing a light-emitting display device, the method including forming a first electrode on a substrate, the substrate including a plurality of pixel regions divided by a non-pixel region, in each of the pixel regions; forming a pixel defining layer, the pixel defining layer having a plurality of pixel openings, each of the pixel openings exposing the first electrode, on the substrate; forming a hole injection layer on the first electrode; forming a lyophilic layer on the hole injection layer to completely overlap the hole injection layer; forming a hole transport layer on the lyophilic layer; forming a light-emitting layer on the hole transport layer; and forming a second electrode on the light-emitting layer.

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2015-0071721, filed on May 22, 2015, inthe Korean Intellectual Property Office, and entitled: “Method ofManufacturing Light-Emitting Display Device and Light-Emitting DisplayDevice Manufactured Using the Method,” is incorporated by referenceherein in its entirety.

BACKGROUND

1. Field

Embodiments relate to a method of manufacturing a light-emitting displaydevice and a light-emitting display device manufactured using themethod.

2. Description of the Related Art

Among light-emitting display devices, organic light-emitting displaydevices, which may be self-luminous display devices, may provide wideviewing angle, high contrast, and fast response speed.

An organic light-emitting display device may include a light-emittinglayer made of an organic light-emitting material between an anode and acathode. When positive and negative voltages are respectively applied tothese electrodes, holes may move from the anode to the light-emittinglayer via a hole injection layer and a hole transport layer, andelectrons may move from the cathode to the light-emitting layer via anelectron injection layer and an electron transport layer. The electronsand the holes may recombine in the light-emitting layer to generateexcitons. As the excitons change from an excited state to a groundstate, the light-emitting layer may emits light, and an image may bedisplayed.

SUMMARY

Embodiments may be realized by providing a method of manufacturing alight-emitting display device, the method including forming a firstelectrode on a substrate, the substrate including a plurality of pixelregions divided by a non-pixel region, in each of the pixel regions;forming a pixel defining layer, the pixel defining layer having aplurality of pixel openings, each of the pixel openings exposing thefirst electrode, on the substrate; forming a hole injection layer on thefirst electrode; forming a lyophilic layer on the hole injection layerto completely overlap the hole injection layer by forming a lyophilicmaterial layer, whose portion in contact with the hole injection layeris cured by light, on the hole injection layer, placing an open mask,the open mask including an opening region and a blocking region locatedoutside the opening region, above the pixel defining layer such that theopening region overlaps the pixel regions and the non-pixel region, andirradiating the light to the lyophilic material layer; forming a holetransport layer on the lyophilic layer; forming a light-emitting layeron the hole transport layer; and forming a second electrode on thelight-emitting layer.

The lyophilic material layer may include a first portion contacting asurface of the hole injection layer and a second portion contacting asurface of the pixel defining layer.

The lyophilic material layer may be formed using a slit coating method.

Forming the lyophilic layer may further include removing the secondportion using a developing solution after irradiating the light to thelyophilic material layer.

An entirety of the lyophilic material layer may contact the holeinjection layer within each of the pixel openings of the pixel defininglayer.

The lyophilic material layer may be formed using an inkjet printingmethod or a nozzle printing method.

The lyophilic material layer may include one or more of olefin,acrylate, methacrylate, vinyl ether, quinone, benzophenone, benzoinether, aryl ketone, peroxide, biimidazole, benzyl dimethyl ketal,hydroxyl alkyl phenyl acetophone, dialkoxy actophenone, trimethylbenzoylphosphine oxide derivatives, aminoketone, benzoyl cyclohexanol, methylthiophenyl morpholino ketone, morpholino phenyl amino ketone, alphahalogeno acetophenone, oxysulfonyl ketone, sulfonyl ketone, oxysulfonylketone, sulfonyl ketone, benzoyl oxime ester, thioxanthone,camphorquinone, ketocoumarin, or Michler's ketone.

The hole injection layer may include one or more of4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (MTDATA), copperphthalocyanine (CuPc), polyaniline (PANI), orpoly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS).

Forming the hole injection layer may be performed using an inkjetprinting method or a nozzle printing method.

Forming the hole transport layer may be performed using an inkjetprinting method or a nozzle printing method.

The pixel defining layer may include an insulating material thatcontains fluorine.

The opening region of the open mask may consist of one opening.

The light may be ultraviolet (UV) light.

Embodiments may be realized by providing light-emitting display device,including a substrate including a plurality of pixel regions divided bya non-pixel region; a first electrode on the substrate in each of thepixel regions; a pixel defining layer on the substrate and including aplurality of pixel openings, each of the pixel openings exposing thefirst electrode; a hole injection layer on the first electrode in eachof the pixel openings; a lyophilic layer on the hole injection layer,the lyophilic layer completely overlapping the hole injection layer andincluding a material whose portion in contact with the hole injectionlayer reacts to light; a hole transport layer on the lyophilic layer; alight-emitting layer on the hole transport layer; and a second electrodeon the light-emitting layer

The lyophilic layer may be in each of the pixel openings

The lyophilic layer may be formed in a same pattern as the holeinjection layer.

The lyophilic layer may include one or more of olefin, acrylate,methacrylate, vinyl ether, quinone, benzophenone, benzoin ether, arylketone, peroxide, biimidazole, benzyl dimethyl ketal, hydroxyl alkylphenyl acetophone, dialkoxy actophenone, trimethylbenzoyl phosphineoxide derivatives, aminoketone, benzoyl cyclohexanol, methyl thiophenylmorpholino ketone, morpholino phenyl amino ketone, alpha halogenoacetophenone, oxysulfonyl ketone, sulfonyl ketone, oxysulfonyl ketone,sulfonyl ketone, benzoyl oxime ester, thioxanthone, camphorquinone,ketocoumarin, or Michler's ketone.

The hole injection layer may include one or more of4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (MTDATA), copperphthalocyanine (CuPc), polyaniline (PANI), orpoly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS).

The pixel defining layer may include an insulating material thatcontains fluorine.

The light-emitting display device may further include one or more of anelectron transport layer or an electron injection layer between thelight-emitting layer and the second electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describingin detail exemplary embodiments with reference to the attached drawingsin which:

FIGS. 1 through 13 illustrate cross-sectional views of operations of amethod of manufacturing a light-emitting display device according to anembodiment; and

FIGS. 14 through 17 illustrate cross-sectional views of the operation offorming a lyophilic layer in a method of manufacturing a light-emittingdisplay device according to an embodiment.

DETAILED DESCRIPTION

Example embodiments will now be described more fully hereinafter withreference to the accompanying drawings; however, they may be embodied indifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey exemplary implementations to those skilled in the art.

In the drawing figures, the dimensions of layers and regions may beexaggerated for clarity of illustration. It will also be understood thatwhen a layer or element is referred to as being “on” another layer orsubstrate, it can be directly on the other layer or substrate, orintervening layers may also be present. Further, it will be understoodthat when a layer is referred to as being “under” another layer, it canbe directly under, and one or more intervening layers may also bepresent. In addition, it will also be understood that when a layer isreferred to as being “between” two layers, it can be the only layerbetween the two layers, or one or more intervening layers may also bepresent. Like reference numerals refer to like elements throughout.

It will be understood that, although the terms first, second, third,etc., may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or section.

FIGS. 1 through 13 illustrate cross-sectional views of operations of amethod of manufacturing a light-emitting display device according to anembodiment.

Referring to FIG. 1, a substrate 105 may include a plurality of pixelregions PX divided by a non-pixel region NPX. A first electrode 110 maybe formed on the substrate 105 in each pixel region PX.

The substrate 105 may include an insulating substrate. The insulatingsubstrate may be made of a transparent glass material containing SiO₂ asits main component. In some embodiments, the insulating substrate may bemade of an opaque material or a plastic material. Further, theinsulating substrate may be a flexible substrate.

The substrate 105 may further include other structures formed on theinsulating substrate. Examples of the structures include wirings,electrodes, and insulating layers. In some embodiments, the substrate105 may include a plurality of thin-film transistors (TFTs) formed onthe insulating substrate. Each of at least some of the TFTs may have adrain electrode electrically connected to the first electrode 110. Eachof the TFTs may include an active region made of amorphous silicon,polycrystalline silicon or monocrystalline silicon. In an embodiment,each of the TFTs may include an active region made of an oxidesemiconductor.

The pixel regions PX of the substrate 105 may be arranged in a matrix.The pixel regions PX may be regions where light is substantially visibleand may be light-emitting regions. In some embodiments, the pixelregions PX may include a red pixel region which may emit red light, agreen pixel region which may emit green light, and a blue pixel regionwhich may emit blue light.

The non-pixel region may divide the pixel regions PX. The non-pixelregion NPX may be a region where light is not visible and may be anon-light-emitting region. Accordingly, the non-pixel region NPX may notinclude a light-emitting structure for light emission. In someembodiments, the non-light-emitting region may include a light-emittingstructure in at least part thereof and may be a region where lightemission is blocked by a light-blocking structure.

The pixel regions PX and the non-pixel region NPX may be included in adisplay area of a light-emitting display device 100 (see FIG. 13). Thedisplay area may be where an image is displayed, and a non-display areawhere no image is displayed may be disposed around the display area.Various circuit units for driving the light-emitting display device 100(see FIG. 13) may be included in the non-display area.

The first electrode 110 may be formed by depositing and patterning aconductive material or a reflective material on the substrate 105.

The first electrode 110 may include a conductive material having arelatively higher work function than a second electrode 190 (see FIG.13). Examples of the conductive material include indium tin oxide (ITO),indium zinc oxide (IZO), zinc oxide (ZnO), and indium oxide (In₂O₃).These example conductive materials have relatively high work functionsand transparent properties, and if the light-emitting display device 100(see FIG. 13) is of a bottom emission type or a dual emission type, thefirst electrode 110 may be formed as a conductive layer containing atleast one of the above conductive materials or a stacked layer of theabove conductive materials.

If the light-emitting display device 100 (see FIG. 13) is of a topemission type, the first electrode 110 may further include a reflectivematerial together the above conductive materials. Examples of thereflective material include silver (Ag), magnesium (Mg), aluminum (Al),platinum (Pt), lead (Pd), gold (Au), nickel (Ni), neodymium (Nd),iridium (Ir), chrome (Cr), lithium (Li), calcium (Ca), and mixturesthereof. Therefore, the first electrode 110 may be have a monolayerstructure composed of at least one of the above conductive andreflective materials or a multilayer structure composed of a stack ofthe above conductive and reflective materials. If the first electrode110 has a multilayer structure, a topmost layer adjacent to a holeinjection layer 130 (see FIG. 13) may be made of a conductive materialhaving a high work function. For example, the first electrode 110 mayhave a multilayer structure such as, for example, ITO/Mg, ITO/MgF,ITO/Ag, or ITO/Ag/ITO.

Referring to FIG. 2, a pixel defining layer 120 may be formed on thesubstrate 105. The pixel defining layer 120 may define each pixel regionPX and may have a plurality of pixel openings 121, each exposing thefirst electrode 110. The pixel defining layer 120 may be formed bydepositing an insulating material on the whole surface of the substrate105 using a deposition method to cover the first electrode 110 andpatterning the deposited insulating material.

The pixel defining layer 120 may be formed to have a lyophobic propertysuch that a hole injection solution 130 a (see FIG. 3) cannot flow outof the pixel openings 121 of the pixel defining layer 120 when a holeinjection layer 130 is formed by ejecting the hole injection solution130 a (see FIG. 3) into the pixel openings 121 of the pixel defininglayer 120 using an inkjet printing method or a nozzle printing method.For example, the pixel defining layer 120 may be made of an insulatingmaterial that may cause a contact angle of the hole injection solution130 a to the pixel defining layer 120 to be approximately 40 degrees ormore. For example, the pixel defining layer 120 may be made of anorganic insulating material that contains fluorine. The organicinsulating material may include one or more of benzocyclobutene (BCB),polyimide (PI), polyamide (PA), acrylic resin, or phenolic resin. Thepixel defining layer 120 may be formed using, for example, aphotolithography method. The inkjet printing method may be a method ofdropping a solution to be printed onto a desired location in the form ofink droplets. The nozzle printing method may be a method of making asolution to be printed flow along a line including a desired location.

Referring to FIGS. 3 and 4, the hole injection layer 130 may be formedon the first electrode 110.

Referring to FIG. 3, the hole injection solution 130 a may be ejectedfrom an ejection device 10 into each of the pixel openings 121 of thepixel defining layer 120 using a printing method such as an inkjetprinting method and then dried, and the hole injection layer 130 may beformed on the first electrode 110 inside each of the pixel openings 121of the pixel defining layer 120, as illustrated in FIG. 4. In someembodiments, the hole injection solution 130 a may be ejected from theejection device 10 into each of the pixel openings 121 of the pixeldefining layer 120 using a nozzle printing method.

The hole injection layer 130 may include an organic compound such as oneor more of, for example,4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (MTDATA), copperphthalocyanine (CuPc), polyaniline (PANI), orpoly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS).

Referring to FIGS. 5 through 8, a lyophilic layer 140 may be formed onthe first electrode 110 using an open mask OM.

Referring to FIG. 5, a lyophilic material layer 140 a may be formed bycoating a lyophilic solution not only on the first electrode 110 butalso on the whole surface of the pixel defining layer 120 using, e.g.,slit coating. The lyophilic material layer 140 a may be made of amaterial whose portion in contact with the hole injection layer 130 iscured by light. The light may be ultraviolet (UV) light.

Referring to FIG. 6, the open mask OM may be placed above the pixeldefining layer 120 to face the pixel defining layer 120, and then lightmay be irradiated to the lyophilic material layer 140 a. In FIG. 6,arrows indicate light irradiated and passing through the open mask OM.

The open mask OM may include a blocking region BR which may block lightand an opening region OR which may allow light to pass therethrough. Theblocking region BR may be ring-shaped, and the opening region OR may bean opening and defined by the blocking region BR. For example, theblocking region BR may be located outside the opening region OR. Theopening region OR may consist of one opening that is large enough tooverlap the pixel regions PX and the non-pixel region NPX.

The open mask OM may be placed above the pixel defining layer 120 suchthat the opening region OR of the open mask OM may overlap the pixelregions PX and the non-pixel region NPX, and light may be irradiated tothe lyophilic material layer 140 a. Then, the lyophilic material layer140 a may be exposed to the light. A first portion 140 aa of thelyophilic material layer 140 a which directly contacts a surface of thehole injection layer 130 may react to the light (e.g., changes at leastchemically or physically) and may be cured, whereas a second portion 140ab which does not contact the hole injection layer 130 (e.g., contacts asurface of the pixel defining layer 120) may not react to the light andmay have high softening properties. For example, the first portion 140aa may have low solubility, dispersibility, fluidity, mobility, adhesionor absorbency for a developing solution 20 a (see FIG. 7), whereas thesecond portion 140 ab may have high solubility, dispersibility,fluidity, mobility, adhesion or absorbency for the developing solution20 a (see FIG. 7).

The lyophilic material layer 140 a may include one or more of, forexample, olefin, acrylate, methacrylate, vinyl ether, quinone,benzophenone, benzoin ether, aryl ketone, peroxide, biimidazole, benzyldimethyl ketal, hydroxyl alkyl phenyl acetophone, dialkoxy actophenone,trimethylbenzoyl phosphine oxide derivatives, aminoketone, benzoylcyclohexanol, methyl thiophenyl morpholino ketone, morpholino phenylamino ketone, alpha halogeno acetophenone, oxysulfonyl ketone, sulfonylketone, oxysulfonyl ketone, sulfonyl ketone, benzoyl oxime ester,thioxanthone, camphorquinone, ketocoumarin, or Michler's ketone.

Referring to FIG. 7, the developing solution 20 a may be sprayed from aspray device 20 toward the lyophilic material layer 140 a, and thesecond portion 140 ab of the lyophilic material layer 140 a may beremoved, leaving only the first portion 140 aa. Accordingly, thelyophilic layer 140 may be formed in each of the pixel openings 121 ofthe pixel defining layer 120 to completely overlap the hole injectionlayer 130, as illustrated in FIG. 8.

The lyophilic layer 140 may have a contact angle of approximately 20degrees or less with respect to a hole transport solution 150 a (seeFIG. 9), and the hole transport solution 150 a (see FIG. 9) may havehigh wettability for the lyophilic layers 140 a. Accordingly, a holetransport layer 150 (see FIG. 10) may be evenly formed on the lyophiliclayer 140 inside each of the pixel openings 121 of the pixel defininglayer 120.

As described above, even if the whole of the lyophilic material layer140 a is exposed to light, only the first portion 140 aa which directlycontacts the hole injection layer 130 may react to and may be cured bylight, whereas the second portion 140 ab which does not contact the holeinjection layer 130 may not react to the light and may have softeningproperties. Accordingly, the developing solution 20 a sprayed over thelyophilic material layer 140 a may remove the second portion 140 ab,leaving only the first portion 140 aa, the lyophilic layer 140 may beformed inside each of the pixel openings 121 of the pixel defining layer120, and there may be no need for a pattern mask having a complicatedpattern. Instead, the open mask OM having a simple structure without apattern may be used to prevent light irradiated to the lyophilicmaterial layer 140 a from leaking to unnecessary regions.

The open mask OM may be reused even if a model of a light-emittingdisplay device is changed. Therefore, it may not be necessary to changemasks whenever the model of the light-emitting display device ischanged, and the entire process may be simplified.

Referring to FIGS. 9 and 10, the hole transport layer 150 may be formedon the lyophilic layer 140.

Referring to FIG. 9, the hole transport solution 150 a may be ejectedfrom an ejection device 30 into each of the pixel openings 121 of thepixel defining layer 120 using a printing method such as an inkjetprinting method and then dried, and the hole transport layer 150 may beformed on the lyophilic layer 140 inside each of the pixel openings 121of the pixel defining layer 120, as illustrated in FIG. 10. In someembodiments, the hole transport solution 150 a may be ejected from theejection device 30 into each of the pixel openings 121 of the pixeldefining layer 120 using a nozzle printing method.

The hole transport layer 150 may be made of an organic compound such as,for example,N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-bi-phenyl-4,4′-diamine (TPD)or N,N′-di(naphthalene-1-yl)-N,N′-diphenyl-benzidine (NPB).

Referring to FIGS. 11 and 12, a light-emitting layer 160 may be formedon the hole transport layer 150.

Referring to FIG. 11, a light-emitting solution 160 a may be ejectedfrom an ejection device 40 into each of the pixel openings 121 of thepixel defining layer 120 using a printing method such as an inkjetprinting method and then dried, and the light-emitting layer 160 may beformed on the hole transport layer 150 inside each of the pixel openings121 of the pixel defining layer 120, as illustrated in FIG. 12. In someembodiments, the light-emitting solution 160 a may be ejected from theejection device 40 into each of the pixel openings 121 of the pixeldefining layer 120 using a nozzle printing method.

The light-emitting layer 160 may include a red light-emitting layerwhich may emit red light, a green light-emitting layer which may emitgreen light, and a blue light-emitting layer which may emit blue light.

The red light-emitting layer may include one red light-emitting materialor a host and a red dopant. Examples of the host of the redlight-emitting layer may include, for example,tris(8-hydroxyquinolinato)aluminium (Alq₃),4,4′-N,N′-dicarbazol-biphenyl (CBP), ploy(n-vinylcarbazole) (PVK),9,10-Di(naphthyl-2-yl)anthracene (ADN),4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBI),3-tert-butyl-9,10-di(naphth-2-yl) anthracene (TBADN), ter-fluorene (E3),and distyrylarylene (DSA). Examples of the red dopant may include, forexample, PtOEP, Ir(piq)₃, and Btp₂Ir(acac).

The green light-emitting layer may include one green light-emittingmaterial or a host and a green dopant. The host of the redlight-emitting layer may be used as the host of the green light-emittinglayer. Examples of the green dopant may include, for example, Ir(ppy)₃,Ir(ppy)₂(acac), and Ir(mpyp)₃.

The blue light-emitting layer may include one blue light-emittingmaterial or a host and a blue dopant. The host of the red light-emittinglayer may be used as the host of the blue light-emitting layer. Examplesof the blue dopant may include, for example, F₂Irpic, (F₂ppy)₂Ir(tmd),Ir(dfppz)₃, ter-fluorene (E3), 4,4′-bis(4-di-p-tolylaminostyryl)biphenyl (DPAVBi), and 2,5,8,11-tetra-tert-butyl perylene (TBPe).

Referring to FIG. 13, an electron transport layer 170, an electroninjection layer 180, and the second electrode 190 may be formed on thelight-emitting layer 160. The electron transport layer 170, the electroninjection layer 180 and the second electrode 190 may be formedsuccessively using a deposition method.

The electron transport layer 170 may be made of an organic compound suchas, for example, 4,7-diphenyl-1,10-phenanthroline (Bphen),aluminum(III)bis(2-methyl-8-hydroxyquinolinato)4-phenylphenolate (BAlq),tris(8-quinolinolato)aluminum (Alq3),berylliumbis(benzoquinolin-10-olate) (Bebq₂), or1,3,5-tris(N-phenylbenzimidazole-2-yl)benzene (TPBI).

The electron injection layer 180 may be made of, for example, LiF orCsF.

The second electrode 190 may include a conductive material having arelatively lower work function than the first electrode 110. Forexample, the second electrode 150 may include Li, Ca, LiF/Ca, LiF/Al,Al, Mg, Ag, Pt, Pd, Ni, Au, Nd, Ir, Cr, BaF, Ba, or any mixture orcompound (e.g., a compound of Ag and Mg) thereof. The second electrode190 may further include an auxiliary electrode. The auxiliary electrodemay include a layer formed by depositing at least one of the abovematerials and transparent metal oxide (such as ITO, IZO, ZnO, or indiumtin zinc oxide (ITZO)) formed on the layer.

If the light-emitting display device 100 is of a bottom emission type,the second electrode 190 may include only a conductive layer having alow work function or may further include a reflective material layerformed on the conductive layer. If the light-emitting display device 100is of a top emission type, the second electrode 190 may further includea transparent conductive layer (such as an ITO layer, an IZO layer, aZnO layer, or an In₂O₃ layer) formed on the thin conductive layer.

The method of manufacturing a light-emitting display device according tothe current embodiment may further include placing an encapsulationsubstrate on the second electrode 190. The method of manufacturing alight-emitting display device according to the current embodiment mayfurther include placing a spacer between the second electrode 190 andthe encapsulation substrate. Since various methods of placing theencapsulation substrate and placing the spacer may be readily determinedby those of skill in the art, a detailed description thereof is omitted.

As described above, in the method of manufacturing a light-emittingdisplay device according to the current embodiment, the lyophilicmaterial layer 140 a whose portion in contact with the hole injectionlayer 130 may react to light may be placed on the hole injection layer130, an exposure process may then be performed using the unpatternedopen mask OM, and the lyophilic layer 140 may be formed in each of thepixel openings 121 of the pixel defining layer 120. Therefore, the openmask OM may be reused even if the model of a light-emitting displaydevice is changed, and the entire process may be simplified.

A light-emitting display device 100 manufactured using the manufacturingmethod of FIGS. 1 through 13 may include a substrate 105, a firstelectrode 110, a pixel defining layer 120, a hole injection layer 130, alyophilic layer 140, a hole transport layer 150, a light-emitting layer160, an electron transport layer 170, an electron injection layer 180,and a second electrode 190.

Since the substrate 105 has been described above in detail, a redundantdescription thereof is omitted.

The first electrode 110 may be disposed on the substrate 105 in eachpixel region PX. The first electrode 110 may be an anode that mayprovide holes to the light-emitting layer 160 in response to a signaltransmitted to a drain electrode of a TFT disposed on the substrate 105.

The pixel defining layer 120 may be formed on the substrate 105 todefine each pixel region PX and may have a plurality of pixel openings121, each exposing the first electrode 110. The pixel defining layer 120may allow the hole injection layer 130 to be formed on the firstelectrode 110 through each of the pixel openings 121.

The hole injection layer 130 may be disposed on the first electrode 110inside each of the pixel openings 121 of the pixel defining layer 120.The hole injection layer 130 may be a buffer layer that may lower anenergy barrier between the first electrode 110 and the hole transportlayer 150. The hole injection layer 130 may allow holes received fromthe first electrode 110 to be easily injected into the hole transportlayer 150.

The lyophilic layer 140 may be formed on the hole injection layer 130inside each of the pixel openings 121 of the pixel defining layer 120 tocompletely overlap the hole injection layer 130. The lyophilic layer 140may be formed in the same pattern as the hole injection layer 130. Thelyophilic layer 140 may increase the wettability of a hole transportsolution 150 a (see FIG. 9) for the lyophilic layer 140, such that thehole transport layer 150 may be uniformly formed inside each of thepixel openings 121 of the pixel defining layer 120.

The hole transport layer 150 may be disposed on the lyophilic layer 140inside each of the pixel openings 121 of the pixel defining layer 120.The hole transport layer 150 may deliver holes received through the holeinjection layer 130 to the light-emitting layer 160.

The light-emitting layer 160 may be disposed on the hole transport layer150 inside each of the pixel openings 121 of the pixel defining layer120. The light-emitting layer 160 may emit light when holes receivedfrom the first electrode 110 and electrons received from the secondelectrode 190 recombine. For example, holes and electrons provided tothe light-emitting layer 160 may combine to form excitons. When theexcitons change from an excited state to a ground state, thelight-emitting layer 160 may emit light.

The electron transport layer 170 may be disposed on the light-emittinglayer 160. The electron transport layer 170 may deliver electronsreceived from the second electrode 190 via the electron injection layer180 to the light-emitting layer 160.

The electron injection layer 180 may be disposed on the electrontransport layer 170. The electron injection layer 180 may be a bufferlayer that may lower an energy barrier between the electron transportlayer 170 and the second electrode 190. The electron injection layer 180may allow electrons received from the second electrode 190 to be easilyinjected into the electron transport layer 170.

The second electrode 190 may be disposed on the electron injection layer180 and may be a cathode that may provide electrons to thelight-emitting layer 160.

A method of manufacturing a light-emitting display device according toan embodiment will now be described.

FIGS. 14 through 17 illustrate cross-sectional views of the operation offorming a lyophilic layer 140 in a method of manufacturing alight-emitting display device according to an embodiment.

The method of manufacturing a light-emitting display device according tothe current embodiment is the same as the method of manufacturing alight-emitting display device according to the embodiment of FIGS. 1through 13 except for the operation of forming the lyophilic layer 140.Accordingly, the method of manufacturing a light-emitting display deviceaccording to the current embodiment will be described, focusing mainlyon the operation of forming the lyophilic layer 140.

Referring to FIGS. 14 through 17, the lyophilic layer 140 may be formedon a first electrode 110 using an open mask OM.

Referring to FIG. 14, a lyophilic solution 140 ba may be ejected from anejection device 50 into each pixel opening 121 of a pixel defining layer120 using a printing method such as an inkjet printing method and thendried, and a lyophilic material layer 140 b may be disposed only on thefirst electrode 110 as illustrated in FIG. 15. For example, the whole,e.g., an entirety, of the lyophilic material layer 140 b may contact ahole injection layer 130. The lyophilic material layer 140 b may be madeof the same material as the lyophilic material layer 140 a of FIG. 5.

Referring to FIG. 16, the open mask OM may be placed above the pixeldefining layer 120 to face the pixel defining layer 120, and then lightmay be irradiated to the lyophilic material layer 140 b. In FIG. 16,arrows indicate light irradiated and passing through the open mask OM.

The open mask OM may be placed above the pixel defining layer 120 suchthat an opening region OR of the open mask OM may overlap pixel regionsPX and a non-pixel region NPX, light may be irradiated to the lyophilicmaterial layer 140 a, and the lyophilic material layer 140 a may beexposed to the light. The lyophilic material layer 140 b may react tothe light and may be cured. Accordingly, the lyophilic layer 140 may beformed on the hole injection layer 130 to completely overlap the holeinjection layer 130, as illustrated in FIG. 17. The open mask OM may beused to prevent the light irradiated to the lyophilic material layer 140a from leaking to unnecessary regions.

As described above, the lyophilic material layer 140 b may be formedonly on the hole injection layer 130 using a printing method, and thelyophilic layer 140 may be formed inside each pixel opening 121 of thepixel defining layer 120 without the process of spraying the developingsolution 20 a in FIG. 7.

In the method of manufacturing a light-emitting display device accordingto the current embodiment, the lyophilic material layer 140 b may beplaced only on the hole injection layer 130, an exposure process maythen be performed using the unpatterned open mask OM, and the lyophiliclayer 140 may be formed inside each pixel opening 121 of the pixeldefining layer 120. Therefore, the open mask OM may be reused even ifthe model of a light-emitting display device is changed, and the entireprocess may be simplified.

By way of summation and review, an organic light-emitting display devicemay include a pixel defining layer having an opening that exposes theanode formed in each of a plurality of pixel regions. The hole injectionlayer, the hole transport layer, the light-emitting layer, the electrontransport layer, the electron injection layer, and the cathode may beformed on the anode exposed through the opening of the pixel defininglayer. For example, the hole transport layer and the organiclight-emitting layer may be formed using an inkjet printing method or anozzle printing method.

A lyophilic layer having lyophilic properties may be formed on the anodeto improve wettability of a hole transport solution. The lyophilic layermay be formed by a photolithography process using a pattern mask thatmay include a plurality of light-transmitting portions (e.g., aplurality of openings) corresponding to the pixel regions.

However, when the model of the light-emitting display device is changed,pattern masks may need to be changed. A new pattern mask may need to bemanufactured, which may not only be cumbersome but may also increasecosts. In addition, it may not be easy to manage pattern masks.Moreover, additional processes may be required for the replacement ofpattern masks.

Provided is a method of manufacturing a light-emitting display devicethat may be capable of simplifying the entire process by not requiring achange of masks when a model of a light-emitting display device ischanged. Provided is a light-emitting display device manufactured usinga method of manufacturing a light-emitting display device that may becapable of simplifying the entire process by not requiring a change ofmasks for each model.

In a method of manufacturing a light-emitting display device accordingto an embodiment, a lyophilic material layer whose portion in contactwith a hole injection layer may react to light may be placed on the holeinjection layer, and a lyophilic layer may be formed in each pixelopening of a pixel defining layer by performing an exposure processusing an unpatterned open mask. Therefore, when a model of alight-emitting display device is changed, the open mask may be reused,and the entire process may be simplified.

Example embodiments have been disclosed herein, and although specificterms are employed, they are used and are to be interpreted in a genericand descriptive sense only and not for purpose of limitation. In someinstances, as would be apparent to one of skill in the art as of thefiling of the present application, features, characteristics, and/orelements described in connection with a particular embodiment may beused singly or in combination with features, characteristics, and/orelements described in connection with other embodiments unless otherwisespecifically indicated. Accordingly, it will be understood by those ofskill in the art that various changes in form and details may be madewithout departing from the spirit and scope of the present invention asset forth in the following claims.

What is claimed is:
 1. A method of manufacturing a light-emittingdisplay device, the method comprising: forming a first electrode on asubstrate, the substrate including a display area including plurality ofpixel regions divided by a non-pixel region in each of the pixelregions; forming a pixel defining layer, the pixel defining layer havinga plurality of pixel openings, each of the pixel openings exposing thefirst electrode, on the substrate; forming a hole injection layer on thefirst electrode; forming a lyophilic layer on the hole injection layerto completely overlap the hole injection layer by forming a lyophilicmaterial layer, whose portion in contact with the hole injection layeris curable by light, on the hole injection layer, placing an open mask,the open mask including an opening region and a blocking region locatedoutside the opening region, and the open mask being above the pixeldefining layer such that the opening region overlaps an entirety of thepixel regions and the non-pixel region, and irradiating the light to thelyophilic material layer such that the pixel regions and the non-pixelregion are entirely irradiated; forming a hole transport layer on thelyophilic layer; forming a light-emitting layer on the hole transportlayer; and forming a second electrode on the light-emitting layer. 2.The method as claimed in claim 1, wherein the lyophilic material layerincludes a first portion contacting a surface of the hole injectionlayer and a second portion contacting a surface of the pixel defininglayer.
 3. The method as claimed in claim 2, wherein the lyophilicmaterial layer is formed using a slit coating method.
 4. The method asclaimed in claim 2, wherein forming the lyophilic layer further includesremoving the second portion using a developing solution afterirradiating the light to the lyophilic material layer.
 5. The method asclaimed in claim 1, wherein an entirety of the lyophilic material layercontacts the hole injection layer within each of the pixel openings ofthe pixel defining layer.
 6. The method as claimed in claim 5, whereinthe lyophilic material layer is formed using an inkjet printing methodor a nozzle printing method.
 7. The method as claimed in claim 1,wherein the lyophilic material layer includes one or more of olefin,acrylate, methacrylate, vinyl ether, quinone, benzophenone, benzoinether, aryl ketone, peroxide, biimidazole, benzyl dimethyl ketal,hydroxyl alkyl phenyl acetophone, dialkoxy actophenone, trimethylbenzoylphosphine oxide derivatives, aminoketone, benzoyl cyclohexanol, methylthiophenyl morpholino ketone, morpholino phenyl amino ketone, alphahalogeno acetophenone, oxysulfonyl ketone, sulfonyl ketone, oxysulfonylketone, sulfonyl ketone, benzoyl oxime ester, thioxanthone,camphorquinone, ketocoumarin, or Michler's ketone.
 8. The method asclaimed in claim 7, wherein the hole injection layer includes one ormore of 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (MTDATA),copper phthalocyanine (CuPc), polyaniline (PANT), orpoly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT/PSS). 9.The method as claimed in claim 1, wherein forming the hole injectionlayer is performed using an inkjet printing method or a nozzle printingmethod.
 10. The method as claimed in claim 1, wherein forming the holetransport layer is performed using an inkjet printing method or a nozzleprinting method.
 11. The method as claimed in claim 1, wherein the pixeldefining layer includes an insulating material that contains fluorine.12. The method as claimed in claim 1, wherein the opening region of theopen mask consists of one opening.
 13. The method as claimed in claim 1,wherein the light is ultraviolet (UV) light.
 14. The method as claimedin claim 1, wherein a first portion of the lyophilic material layercontacting the hole injection layer is cured by the light, wherein asecond portion of the lyophilic material layer contacting the pixeldefining layer is not cured by the light, and wherein the pixel defininglayer is lyophobic.